1. Field of the Invention
The present invention relates to a trash bag. More particularly, the trash bag with the double-layer tying structure for not only providing a relatively enhanced tying strength for the trash bag but also minimizing the overall manufacturing cost of the trash bag.
2. Discussion of the Related Art
Trash is a by-product and is directly linked to the human development. With the advent of large scale disposal of trash, disposable bag are a convenient and sanitary way of handling trash. The disposable bags are usually made of plastic and are used with a trash container to keep the container sanitary by preventing the trash directly contacting with the trash container. The disposable bag generally comprises two bag layers to form an open top and a closed bottom. When the disposable bag is used with the trash container, the open top of the disposable bag is folded back upon itself over the top rim of the trash container. After the disposable bag is filled with trash, the disposable bag is taken out of the trash container and is tied to seal the cavity of the disposable bag. The major problem of the disposable bag is how to ensure the open top of the disposable bag being closed tightly for preventing the trash being leaked out of the disposable bag.
A first type of disposable bag comprises two wrappers provided at two bag layers respectively at the open top, wherein the wrappers are then tied with each other to form a knot which closes the open top of the disposable bag. The problem of such wrappers is that each wrapper has a single-layer structure. Therefore, the wrappers will be easily torn off from the bag layers when the pulling force is exerted at the wrappers to form the knot. Further, the cavity of the disposable bag cannot be tightly sealed even though the wrappers are tightly tied.
A second type of disposable bag comprises a bendable metal wire to tie at the neck portion of the disposable bag. The advantage of the tying wire is that the disposable bag can be tightly closed to seal the cavity by tying the tying wire at the neck portion of the disposable bag. However, the problem of such tying wire is that the bag manufacturer must provide additional components to incorporate with the disposable bag, which will highly increase the cost of the disposable bag. In addition, the user must pull additional effort to keep the tying wire in a secure way because the disposable bag cannot be closed without the tying wire. Therefore, if the user misplaces the tying wires or unintentionally uses extra tying wire, the disposable bags will not be closed by the tying wires.
A third type of disposable bag comprises a tying band extending around the open top of the disposable bag, wherein the tying band can be pulled to tie and close the open top of the disposable bag. In order to incorporate with the tying band, the disposable bag has a channel formed at the open top for the tying band to slide along the channel. Obviously, the manufacturing cost and process of such disposable will be highly increased and complicated by adding the tying band as the additional component and by forming the channel at the open top of the disposable bag.